'set' local variables within a proc before it runs

proc_injector.rb

# @param args [Hash{Symbol=>Object}]
def run_proc_with_locals(args, proc)
  k = Class.new
  args.each do |sym, v|
    k.send(:define_method, sym) { v }
  end
  k.new.instance_exec(&proc)
end

tha_proc = proc do
  puts "Hello #{name}"
end

run_proc_with_locals({:name => "world"}, tha_proc)
#=> Hello world